催化三旋失效分析及对策

FAILURE ANALYSIS OF THIRD-STAGE CYCLONE IN FCC UNIT AND THE COUNTERMEASURES

三旋是催化裂化装置能量回收系统的重要设备,其高效运行对烟机及整个催化装置都具有非常重要的意义。镇海某大型催化装置因三旋失效引起烟机入口烟气催化剂粒度超标,曾造成烟机两套转子动叶片磨损,装置不得已停工消缺。文章从卧式三旋的结构特点入手,结合三旋检修情况,分析其失效原因主要是由于三旋排尘泄气系统堵塞造成的窜流返混以及单管结垢,着重分析其形成机理,并制定了相应的对策。

Third-stage cyclone is important to the energy recovery system in FCC unit.Its efficient operation is of great significance to both the flue gas turbine expander and the FCC unit.The failure of thirdstage cyclone in a large-scale FCC unit in Zhenhai led to the over-standard catalyst particle size in the flue gas at the inlet of flue gas turbine expander and caused the wear of two sets of rotor blade,so the unit was shut down.Based on the structure characteristics of horizontal third-stage cyclone and the maintenance of the third-stage cyclone,this article analyzes the reasons for the failure,which is fluid channeling and back mixing as well as single pipe scaling caused by the plugging in the dust exhaust and venting system of third-stage cyclone,analyzes the formation mechanism,and develops corresponding countermeasures.